Acoustic echo cancellation (AEC) is the problem of eliminating, from the signal captured by a microphone, the signals radiated by loudspeakers that are placed in proximity to the microphone. AEC has been an important aspect of bi-directional communication, including teleconferencing systems, speaker phones, and the like. The standard problem scenario includes one loudspeaker and one microphone, and the traditional solution is to train an adaptive filter to remove the indication of loudspeaker feedback. Due to the importance of the problem, increasing convergence speed, detecting convergence state, reducing computational complexity, etc. are areas where research continues to advance.
A second scenario has recently gained importance, namely, voice control for home and automobile entertainment systems. These systems usually have multichannel audio reproduction, e.g., stereo or 5.1 surround systems, operating at fairly high reproduction levels. The user (i.e., the desired sound source) may be several meters away from the microphone, and noise levels can be significant.